Well bore servicing arrangement

ABSTRACT

For use with a top drive power unit supported for connection with a well string in a well bore to selectively impart longitudinal and/or rotational movement to the well string, a feeder for supplying a pumpable substance such as cement and the like from an external supply source to the interior of the well string in the well bore without first discharging it through the top drive power unit including a tubular member or mandrel extending through an outer housing which is sealably and rotatably supported thereon for relative rotation between the outer housing and the tubular member. The mandrel and outer housing have flow passages for communicating the pumpable substance from an external source to discharge through the outer housing and mandrel into the interior of the well string below the top drive power unit. The mandrel includes an arrangement to releasably position a pump down plug for discharge into the well string and for positioning a barrier to selectively dislodge the barrier into the well string through the mandrel.

DESCRIPTION OF THE PRIOR ART

Heretofore in the drilling of well bores for oil and gas wells, asuitable drilling mast has been first positioned on location with acrown block at the top of the mast over which extends a cable from thedraw works drum. The cable extends from the group of pulleys forming thecrown block back and forth through a group of pulleys forming what istermed a travelling block to suspend the travelling block from the crownblock for longitudinal up and down movement relative to the drillingmast and crown block. A swivel is hung on the hook that is rotatablysupported on the travelling block which swivel includes a gooseneck withwhich a drilling fluid line may be connected for discharging fluidthrough the swivel. The swivel includes a tubular member, or stem, thatis rotatably supported in the swivel and a noncircular longitudinallyextending member referred to as a "kelly" is connected at the lower endof the stem, with the lower end of the "kelly" connected to the wellstring.

Rotation is imparted to the well string to drill the well bore by arotary table which is provided with a kelly bushing supported thereinthat engages and rotates the noncircular kelly and the well string. Theswivel is constructed to accommodate rotation of the well string whiledrilling fluid is discharged into the gooseneck from an external sourceand then conducted through the swivel stem, through the kelly anddischarged into the well string.

More recently, the use of a top drive unit, or top drive power unit isemployed to rotate the drill pipe, or well string in the well borerather than employ a rotary table, kelly busing and kelly. In sucharrangement, spaced guide rails extend vertically above the well bore inthe earth's surface and are supported in such position in any suitablemanner such as by securing to a drilling mast or the like. A frame ismovable along the guide rails and supports the top drive power unitthereon. The travelling block, through the hook and swivel support theframe for movement longitudinally along the guide rails. The top drivepower unit includes a motor which is connected by suitable gear meanswith a rotatable member both of which are supported on the frame that ismovable longitudinally along the guide rails and which frame is elevatedor lowered along the guide rails by the elevator and crown block when itis desired to "trip" the drill pipe or well string into or out of thewell bore or when the well string is moved longitudinally in the wellbore during drilling and servicing operations. The stem of the swivelcommunicates with the upper end of the rotatable member of the powerunit in a manner well known to those skilled in the art for supplyingfluid through the top drive unit to the kelly and well string connectedthereto and depending therefrom. The swivel functions in the same manneras it does in those instances where a rotary table is employed to rotatethe drill string by means of a kelly and enables drilling fluid to besupplied to the drill string that is threadedly engaged with the lowerend of the rotatable member of the top drive power unit as the wellstring is rotated or moved up and down. Apparatus referred to aselevators are secured to and suspend from the frame in a suitable mannerwell known in the art, the elevators being employed when it is desiredto lower joints of drill string into the well bore, or remove suchjoints from the well bore.

DESCRIPTION OF THE INVENTION

From time to time well operations require the use of pumpablesubstances, such as cement, epoxy resins, or the like and it may bedesired to supply such pumpable substances to the well string withoutfirst discharging such substances through the swivel and top drive powerunit without interfering with selective desired longitudinal and/orrotational movement of the well string by the top drive unit. Forexample, the practice of setting liners in a casing in a well bore iswell known and has been utilized for many years. There are severalgenerally accepted arrangements for accomplishing such purpose.

In one arrangement, a liner is secured on a tubular member forming partof a well string and a hanger is mounted on the outside of a liner. Thetubular member includes an extension which extends downwardly into theliner and a seal arrangement is positioned between the tubular memberand the liner for accomplishing the cementing as desired.

The liner is supported on the tubular member in a well known mannerwhich enables them to be disconnected and the liner then positioned onthe casing in the well bore in a well known manner. The well string ismanipulated by powering the top drive unit to rotate it, and the wellstring can be reciprocated by raising and lowering the top drive unitfor conditioning the well bore before discharging cement, or anysuitable bonding agent into the well string for securing the liner inplace. The well string and liner can be rotated after the liner hangeris set and before the cement hardens.

Where a top drive power unit, instead of a rotary table, kelly and kellybushing are employed to rotate a well string during well bore servicingoperations, such as for example only, cementing a liner in a well boreit is desirable to conduct the cementing or bonding agent to the wellstring in a manner to by-pass the top drive unit to avoid possibledamage or deleterious affect upon any portion or component of the topdrive power unit.

In some instances, a liner is set in a well bore without hanging it in acasing.

The present invention provides an apparatus and method for accomplishingthe above and other problems.

This invention also relates to a top drive power system wherein thetraditional rotary table, kelly bushing and kelly are not requiredbecause the drill string is rotated directly by the top drive poweredsystem suspended from the travelling block. Such top drive systemspossess many advantages some of which is the fact that about two-thirdsof the connections required with conventional techniques are eliminatedthereby significantly reducing hazard exposure. Further, when drilling,only smooth pipe is rotating at the floor level thus lessening thedanger of heretofore used rotaty equipment.

This invention further relates to a feeder for a top drive power unitsystem having a fixed part and a rotary part. The fixed part surroundsthe rotary part and includes the cement or bonding agent feed line. Therotary part houses the cement pump down plug and the pump down plugholder. The feeder arrangement is interposed between the motor assemblyof the top drive unit and the top of the well string whereby duringcementing the bonding agent is kept away from the drive assembly of thetop drive system so as to prevent fouling by the cement of the top driveunit.

In addition, the invention relates to the method of cementing a wellusing a top drive power unit system including the step of introducingcement bonding agent at a point in the system between the top of thewell string and the bottom of the top drive power unit.

The invention herein broadly relates to an assembly having a top drivearrangement for rotating and longitudinally moving a well string in abore hole including means for feeding cement to the well string in thebore hole in order to set a liner in a casing of the bore holecomprising a feeder means interposed between the bottom of the top drivedrilling arrangement and the top of the drill string or well string, thefeeder including, if desired, upper and lower threaded connections formake-up and break-out respectively between the feeder and the top driveunit and well string. The feeder is provided with at least one cementfeed line from an external supply source in communication with thefeeder means said feeder means having a mandrel mounted for rotationalong with the top drive unit and the well string, said mandrel having apassage to communicate fluid to the well string, said mandrel extendingthrough a housing sealably and rotatably supported thereon toaccommodate relative rotation between said mandrel and housing, saidhousing having port means for communicating with the cement feed line,said mandrel including a pump down plug holder for releasing a plug intothe well string, and means to discharge a barrier into the well stringwhen desired.

Another object of the present invention is to provide a well servicingunit including a mast, a crown block thereon, a cable extending from apowered drum, over the crown block and weaved back and forth between atravelling block to suspend the travelling block from the crown block inthe mast for longitudinal movement relative to the mast, said mastsupporting longitudinal, and preferably substantially vertical, guiderails extending upwardly from the earth's surface adjacent the well witha top drive power unit thereon for rotating a well string and moving itlongitudinally in the well as desired. A swivel is suspended from thetravelling block and supports the top drive unit for longitudinalmovement by the crown block along the guide rails and a feeder isinterposed between the bottom of the top drive unit and the top of thewell string for conveying pumpable substances from an external source ofsupply to the feeder to discharge into the well string withoutconducting it through the top drive unit.

Another object of the present invention is to provide a method ofconducting servicing operations in a well bore, such as cementing,comprising the steps of moving a power unit longitudinally of a mast inorder to accommodate longitudinal movement or reciprocation in the wellbore of a well string suspended from the top drive unit, rotating thepower unit and the associated well string and supplying a pumpablesubstance to the well bore in which the well string is manipulated byintroducing the pumpable substance at a point below the top drive powerunit and into the well string.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a mast arrangement adjacent awell bore with components of the present invention illustrated; and

FIG. 2 is a sectional view primarily in cross section of the feederschematic illustrated in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will be described in detail as it relates to oneservicing operation, namely cementing a liner in a well bore. However,it can be appreciated that the present invention can be employed in anysituation where it is desired to convey a pumpable substance to a wellstring without first conveying it through a top drive power unit whichis connected to the top of the well string to effect longitudinal and/orrotational movement of the well string during the servicing operationsor otherwise during well bore drilling operations while the pumpablesubstance is supplied to the well string.

In one form of cementing operation in a well bore, a column of bondingagent such as a cement slurry is preceded through the well string bywhat is termed a bottom plug and a top plug at the upper end of theslurry is discharged down through the well string. The bottom plugdisplaces fluid in the casing and inhibits combining of the slurry andwell fluid, such bottom plug also enabling the cement slurry to enterthe well bore annulus and cement a liner, for example, in the well boreafter the liner has been lowered into the well bore on a well string andreleased therefrom and hung on the casing.

Attention is first directed to FIG. 1 wherein a mast assembly isreferred to generally by the numeral 41 and includes suitablelongitudinally extending members M supported on the earth's surfaceadjacent the well bore WB in the earth's surface. A well string 16 isshown as extending into the well bore, which well string 16 is connectedat its upper end to the lower end of a feeder 13 as will be described.The member S at the top of the well bore provides a support for useduring "tripping" the pipe, or well string. Schematically illustrated at11 is a crown block which includes a plurality of rotatable pulleys. Asis well known to those skilled in the art, suitable cable means Cextends from a draw works drum DW powered by a draw works which extendsup over the pulleys in the crown block 11 and down to what is termed thetravelling block 17. The cable C extends back and forth between thepulleys in the crown block 11 and travelling block 17, with one end ofthe cable secured to a portion of the mast 10 or a suitable anchorrepresented at 20'.

Laterally spaced, longitudinally extending, preferably vertical, guiderails 14 are supported by the mast 10 and extend longitudinally adjacentthe well bore WB which receives the well string 16 as diagramaticallyrepresented in FIG. 1. A suitable frame 12a is provided for movementalong the spaced guide rails 14, such frame having secured therewith theswivel 24 which is suspended from the hook 18 that in turn is rotatablysupported by the travelling block 17. The swivel 24 is provided with agooseneck 19 for connection with a drilling fluid line 20 wherebydrilling fluid may be supplied from an external source to the swivel fordischarge through the rotatable stem 12b of the top drive power unitschematically represented at 12 which is supported by the frame 12a formovement along the guide rails 14. A suitable power source, the detailsof which are not illustrated, are also supported on the frame 12a forimparting rotation to the rotatable tubular member or hollow stem 12b ofthe top drive power unit, which stem is connected at its upper end witha rotatable tubular member that depends from the swivel 24 and at itslower end to a sub which connects to the upper end of well string 16, ordirectly to the upper end of the well string.

Also suspended from the frame 12a is a pair of diametically opposedsupport members 21 depending from the power unit 12 and having acircular member 21a at their lower end on which are pivotally supportedlinks 21c. The links 21c are pivotally connected at their lower endswith the elevator 23 as illustrated in FIG. 1 of the drawings. Theelevator is employed when the well string is being "tripped", that iswhen it is being lowered into the well bore joint by joint, or removedfrom the well bore by disconnecting one or more joints at a time fromthe well string. Otherwise, while conducting normal drilling operationsor well servicing operations, the elevator 23 merely hangs alongside thewell string 16, as shown so as to not interfere with rotation thereof,or longitudinal movement along with power unit 12. The structure of thepower unit 12 and the arrangement of the various components associatedtherewith are well known to those skilled in the art.

The pumpable substance feeder for conveying pumpable substance from anexternal supply source to the top of the well string 16 while by-passingthe top drive power unit 12 is shown at 13 in FIG. 1 and in greaterdetail in FIG. 2. The feeder means 13 includes a inner tubular member ormandrel 32 which extends longitudinally through outer tubular member orhousing 28. The mandrel 32 is provided with a longitudinally extendingpassageway 43 therethrough which communicates with at least oneintersecting lateral flow passage means 43a through said inner tubularmember intermediate the ends of said longitudinal flow passage. Moreparticularly, the lateral flow passage means 43a is shown in FIG. 2 asbeing positioned in the inner tubular member intermediate the ends ofthe outer tubular member 28.

Where the feeder means 13 is to be employed in a cementing servicingoperation, additional lateral passage means 43b through the innertubular member are provided which is spaced longitudinally relative toone end of the outer housing member 28 whereby a pump down plugpositioning means 27a may be extended across the longitudinal flowpassage 43 for positioning a pump down plug 26 for discharge through thefeeder means 13 into the well string 16 connected with the feeder meansby means of the threads 33 formed adjacent the lower end of the tubularmember 32 for connection with the upper end of the well string 16.Suitable means such as a hand wheel 27 may be connected with the plunger27a for withdrawing the plunger 27a from its position in the passage 43as shown to permit movement of the plug 27 through the feeder 13 intothe well string 16 when desired. The plunger 27a is threadedly andsealably connected in housing 27b that is threaded in passage 43b toaccommodate movement of plunger 27a longitudinally of housing 27b.

Also, an additional lateral passage 43c is provided in the inner tubularmember for receiving the housing 37a therein. The housing is providedwith a passageway 37b having a seat 37c which may be formed by a splitring 38. A ball or barrier 37 is positioned in the housing 37a on theseat 37c as shown and is engaged with the plunger 39 sealably positionedand threadedly engaged in the housing 37a and movable longitudinallythereof by rotating the member 39a. When the stem 39 is movedlongitudinally inwardly of the housing against the ball 37, the splitring 37c is separated to enable the ball to be discharged into thepassage 37b for movement into the well string to accommodate hanging theliner by hydraulic pressure in the well string where such hangingprocedure is desired.

The outer housing 28 is positioned relative to the inner tubular member32 for sealable and relative rotation therebetween. The positioningmeans incudes a lower support or cap A which is secured to the innertubular member 32 by any suitable means such as the threads 32a. A ballbearing arrangement 31 includes the race 33a supported in the cap A toaccommodate axial thrust loads encountered by the feed means 13 and isretained by the lower ring 28b supported on the outer housing 28 by anysuitable means such as the threads 28c as shown. A tapered rollerbearing race 34 is provided adjacent the other end of the outer housing28 as shown and is retained in position by means of the upper cap A'engaged with housing 28 by any suitable means such as threads 32c asshown to carry lateral or side thrust loads.

The seal means 35 and 36 between the inner tubular member 32 and theouter housing 28 is positioned so as to be on each side of, or to spanthe lateral flow passage means 43a. Also, a circumferencial groove asshown at 32d may be formed on the outer periphery or surface of theinner tubular member 32 and a mating groove 28e can be formed on theinner surface of the outer housing 28 to better accommodate continuousfluid flow from an external source of the pumpable substance to thelongitudinal passage 43 in the inner tubular member 32. The upper end ofring 28b serves as a retainer for the lower seal means 36 and a suitableretainer ring 28f may be engaged by threads as shown in the outerhousing 28 for retaining the seal means 35 in position and to assist insupporting.

It can be appreciated that suitable shoulders are provided in the outerhousing 28 on which the seal means 35 and 36 are seated as shown.

An inlet conduit 30 is provided for connection with an external supplysource for receiving the pumpable substance therethrough to discharge itthrough connection 22 and a "WECO" wing fastener 29 which secures thepipe or conduit 30 to the connection 28g that is threadedly secured inthe lateral passage 28h of outer member 28 that communicates with groove28e, groove 32d and the lateral passage means 43a in the inner tubularmember.

The feeder means 13 is connected by suitable means such as threadedconnection 25 to the lower end of the hollow stem 12b of the top drivepower unit 12 whereby rotation and longitudinal movement may betransmitted from the top drive power unit through the feeder means 13 tothe well string 16 connected therewith while the pumpable substance isdischarged to the moving well string 16 without first passing thesubstance through the top drive unit 12.

As previously noted, where well bore servicing operations require theuse of a pumpable substnce that may have deleterious affects on the topdrive power unit 12, the feeder means 13 may be connected with therotatable stem 12b of the top drive power unit and the conduit or pipe30 connected to communicate the pumpable substance through the outerhousing 28 as described herein and as shown in the drawings. In suchsituation, the fluid is not discharged through the swivel 24 and thenthrough the top drive power unit 12, rather the top drive power unit 12is by-passed to avoid contamination or damage thereto. During theservicing operation where movement of the well string may be desired,such as in a cementing operation or in any other operation, the wellstring can be moved longitudinally and rotatably as desired withoutrequiring that the fluid be first discharged through the top drive unit.For example, in cementing operations it may be desirable to conditionthe well bore by manipulating the well string during cementingoperations. Such procedure may be accomplished while still accommodatingflow of the pumpable substance to the well string while by-passing thetop drive unit.

Before the cementing operation is completed, or while it is beingperformed, it sometimes is desirable to rotate the well string in anendeavor to assure a better cementing operation in the well boreadjacent the liner and liner hanger. This also may be accomplished bymeans of the present invention.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in size, shapeand materials as well as in the details of the illustrated constructionmay be made without departing from the spirit of the invention.

What is claimed is:
 1. An assembly for connecting between the hollow,rotatable stem extending through a top drive power unit and a wellstring wherein drilling fluids are supplied to the stem for passagethrough the top drive power unit to the well string therebelow, the wellstring being rotatable and movable longitudinally in a well bore whilesupplying a pumpable substance to the hollow stem and well stringwithout first conducting the substance through the top drive power unit,said assembly comprising:an outer tubular member; a rotatable innertubular member with a longitudinal passage therethrough; said rotatableinner tubular member and longitudinal passage therethrough extendingthrough said outer tubular member; said rotatable inner tubular memberhaving connection means connectable with the hollow stem forcommunicating the longitudinal passage in said inner tubular member withthe hollow stem beneath the top drive power unit and with the wellstring; said outer tubular member having lateral flow passage means tocommunicate with the longitudinal passage extending through said innertubular member; said rotatable inner tubular member having acircumferential groove on its outer surface intersecting said lateralflow passage means and said outer tubular member having a matingcircumferential groove formed on its inner surface which groove meanscooperate to form a continuous fluid flow passage in each said inner andouter tubular members communicating with said lateral passage means;bearing means to accommodate rotation of said inner tubular member bythe top drive power unit relative to said outer tubular member; sealmeans between said rotatable inner tubular member and outer tubularmember on each side of said lateral flow passage means; plunger meansextending through said rotatable inner tubular member into thelongitudinal passage therethrough for restricting access through thelongitudinal passage in said inner rotatable tubular member; and meansfor withdrawing said plunger means from the longitudinal passage in saidrotatable inner tubular member.
 2. The assembly of claim 1including:housing means; means for communicating said housing means tosaid rotatable inner tubular member to communicate with the longitudinalpassage therethrough; ball means supported in said housing; and means toaccommodate movement of said ball means from said housing means into thelongitudinal passage of said inner rotatable tubular member.